Across
- 2. the protein that makes up bones
- 5. The heart is a
- 6. air enters through your nose or
- 8. hold the skeleton together
- 9. The walls of the trachea are strengthened by stiff rings of
- 10. the trachea splits into how many air tubes
- 12. how much does the human body weight
- 13. How long is the spinal cord
- 15. Carries blood away from the heart
- 16. the type of muscle found in the heart
- 17. The heart sends
Down
- 1. the lungs are apart of what system
- 3. protects the brain
- 4. the largest part of the brain
- 6. pull on the joints allowing us to move
- 7. Carry blood back to the heart
- 9. the human brain is incredibly
- 11. humans have how many types of muscles
- 14. a pathway for messages between the brain and the body
- 17. protects organs in our body